Bomba termonucleare B83
La bomba termonucleare B83 (vedi arma termonucleare è un bomba non guidata, a potenza variabile, sviluppata dagli Stati Uniti nei tardi anni 1970, entrando in servizio nell'aviazione americana nel 1983. Con una potenza massima di 1,2 Megatoni (ossia circa 75 volte la potenza di 16 kt della bomba atomica a fissione d'uranio "Little Boy" sganciata su Hiroshima il 6 Agosto 1945), è la più poderosa arma nucleare a caduta libera nell'arsenale degli Stati Uniti. Venne progettata nello LLNL, e il primo test sotterraneo della bomba di serie B83 avvenne il 15 dicembre del 1984. | length = | part_length = | width = | height = | diameter = | filling = | filling_weight = | detonation = | yield = (maximum) }}|}} Storia The B83 was based partly on the earlier B77 program, which was terminated because of cost overruns. The B77 was designed with an active altitude control and lifting parachute system for supersonic low-altitude delivery from the B-1A bomber. B77 nuclear component test firings were attributed to the Operation Anvil (Nuclear test) series in 1975 and 1976, specifically the "Cheese" test shots in Anvil: * Anvil Kasseri – 28 October 1975, (B77/B83 full yield) * Anvil Muenster – 3 January 1976, * Anvil Fontina – 12 February 1976, * Anvil Colby – 14 May 1976, The B83 nuclear components have been attributed as the same as the earlier B77. The B83 replaced several earlier weapons, including the B28, B43, and to some extent the ultra-high-yield B53. It was the first U.S. nuclear weapon designed from the start to avoid accidental detonation, with the use of "insensitive explosives" in the trigger lens system. Its layout is similar to that of the smaller B61, with the warhead mounted in the forward part of the weapon to make the bomb nose-heavy. It was intended for high-speed carriage (up to Mach 2.0) and delivery at high or low altitude. For the latter role, it is equipped with a parachute retardation system, with a Kevlar ribbon parachute capable of rapid deceleration. It can be employed in free-fall, retarded, contact, and laydown modes, for air-burst or ground-burst detonation. Security features include next-generation permissive action link (PAL) and a command disablement system (CDS), rendering the weapon tactically useless without a nuclear yield. The B83 was reportedly test fired in the Grenadier Tierra nuclear weapon test on 15 December 1984, at a reduced yield of 80 kilotonnes due to the Threshold Test Ban Treaty. , the B83 is being considered for reduction in the US nuclear arsenal as a part of a modernization and downsizing program begun in approximately 2010. . Design The bomb is long, with a diameter of . The actual nuclear explosive package, judging from published drawings, occupies some in the forward part of the bomb case. The bomb weighs approximately . The location of the lifting lugs shows that the greater part of the total mass is contained in the nuclear explosive. It has a variable yield: the destructive power is adjustable from somewhere in the low kiloton range up to a maximum of 1.2 megatons (1.2 million tons of TNT). The weapon is protected by a Category "D" Permissive Action Link (PAL) About 650 B83s were built, and the weapon remains in service as part of the United States "Enduring Stockpile". Aircraft capable of carrying the B83 The following aircraft are capable of launching an attack using the B83 bomb: *B-52 *B-1 Lancer *B-2 *FB-111 *F-15E *F-16 *F/A-18 *AV-8B Harrier II Nuclear capability has been removed from the B-1B, though it was tested with the B-61 nuclear bomb in the mid-1980s, as well as with the ACM, Advanced Cruise Missile (now being retired). Novel uses The B83 is one of the weapons considered for use in the "Nuclear Bunker Buster" project, which for a time was known as the Robust Nuclear Earth Penetrator, or RNEP. While most efforts have focused on the smaller B61-11 nuclear bomb, Los Alamos National Laboratory was also analyzing the use of the B83 in this role. The physics package contained within the B83 has been studied for use in asteroid impact avoidance strategies against any seriously threatening near earth asteroids. Six such warheads, configured for the maximum 1.2 Mt yield, would be deployed by maneuvering space vehicles to "knock" an asteroid off course, should it pose a risk to the Earth."NASA plans 'Armageddon' spacecraft to blast asteroid" article at Flightglobal.com In popular culture * In the 1996 film Broken Arrow, two B83 bombs are stolen. * In the strategy game World in Conflict, a B83 is considered the last resort if the U.S. Army failed to retake Seattle from the Soviet Union before the arrival of the PLA naval forces. * In the 2007 film Aliens vs. Predator: Requiem, a B83 bomb is used to destroy a city. * In the Charles Stross alternate-history novel The Revolution Trade, a version of the post-9/11 U.S. carpet bombs a trans-dimensional enemy state using hundreds of B83s. * In the 2016 film Shin Godzilla a B83 warhead is planed to be used to kill Godzilla by the USA See also * B61 * List of nuclear weapons References External links * B83 Information Site * B83 page at nuclearweaponarchive.org * NASA proposal to attack asteroids Fonti * Category:Nuclear bombs of the United States Categoria:Armi nucleari Categoria:Armi della terza guerra mondiale Categoria:Armi del XXI secolo